Reversible scarifier



July 27, 1948. R, BLACKMQRE 2,446,074

REVERSIBLE SCARIFIER Filed Nov. 20, 1945 JFTL.

P T IL Inventor Q ROBERT B. BLAGKMOR Patented July 27, 1948 UNITED STATES PATENT oFFicE REVERSIBLE soimmmn Robert B. Blackmore, lasper,Wyo. A Application November 20, 1945, Serial No. 629,839

3 Claims. 1

The invention relates to a scarifier adapted to :be attached to .a bulldozer machine of the Caterpillar tractor type having an adjustable grader blade.

It is well known that in the operation of a bulldozer of the Caterpillar type, the ground over which the machine repeatedly travels becomes compacted and hard due to tamping effect of the Caterpillar treads. As a consequence when moving earth the machine is constantly working against itself i. e. it iscon-tinuously compacting the very earth which it is later to move.

The primary object of the present invention is to loosen the earth to a suitable depth as the bulldozer moves about and to thereby counteract at least to a certain degree the earth compacting tendency of the bulldozer treads.

Another object is to regulate the depth to which the earth is loosened by such movements and to loosen the earth about and to uproot stones and the like which may be buried beneath the layer of earth which is being moved.

Among its features my invention embodies a plurality of scarifier teeth adapted to be carried by the bulldozer blade, means to hold the teeth on the blade and means to regulate the depth to which each such tooth projects below the lower edge of the bulldozer blade and hence regulate the depth to which the earth, over which the bulldozer is travelling, is loosened.

Other features include teeth which are adapted to enter the reinforcing channels ordinarily carried on the rear curvex face of a bulldozer blade, and means to hold the teeth in various adjusted positions with relation thereto.

Still other features include teeth which may be reversed so that when one cutting or scarifying end becomes dull and worn a fresh cutting surface may be substituted by the simple expedient of turning the tooth upside down.

With these and other objects in view, the invention consists in the features of construction, combination and arrangement of parts, as will be hereinafter more fully described, illustrated in the accompanying drawing, which discloses the preferred embodiment of the invention and pointed out in the claims hereunto appended.

In the accompanying drawing:

Fligure 1 is an elevation of a bulldozer machine blade showing the scarifier constructed in accordance with the invention applied thereto.

Figure 2 is an end view of the blade showing the scarifier by full lines in one position and dotted lines in an adjusted position.

Figure 3 is a fragmentary rear elevation of the blade with the scarifier teeth associated therewith. f Figure .4 is a fragmentary perspective View of the blade looking toward the rear side thereof with a scarifier fitted thereto.

Similar reference characters indicate corresponding parts throughout the several views in the drawings.

Referring to the drawing in detail, the scarifier constituting the present invention comprises a plurality of forwardly bowed tooth bars, each identified generally at A. A group of such tooth bars are arranged rearwardly of a grader blade B, which as usual is suitably attached to a tractor, not shown, with provision for adjustment as to depth of cut and angularity of blade with respect to a roadway in a well known manner.

At the rear side of the blade B at selected intervals are rows of vertically spaced straps or loops [0, one row for each bar, and slidably fitting in each row of said straps or loops lll is a tooth which extends perpendicular to the lower edge of the blade B. Each tooth II is in the form of a steel rail having reversely tapered or beveled digging tips l2, while intermediate these tips.

and extending crosswise of each bar is a series of spaced holes I 3, any one of which is selectively engageable by a locking bolt or key M releasably fitting the intermediate loop or strap III of the particular row of loops in which the tooth bar is held.

By extraction of the bolt l4 its respective bar can be vertically adjusted on the rear face of the blade B so that the lowermost tip 12 will project beneath the bottom edge of the blade to a suitable depth. so that the scarifier will dig into the earth for loosening the layer thereof immediately below the layer that is being moved. It will thus be seen that the compacting effect of the tractor treads is largely overcome and the earth may be removed with comparatively little effort.

The bar A can be raised or lowered and also can be reversed for the functioning thereof with respect to the blade B in the operation of the latter. On reversal a new tip can be brought into action to substitute for a worn tip and in this way a fresh point is made available and the scarifier in the series of the teeth bars can be used on road grading blades and other implements.

It will be understood, of course, that the bulldozer blade may be equipped with the conventional adjustable skids to regulate the depth to 3 which the scarifying blades may cut into the surface traversed.

What is claimed is:

1. The combination with a bulldozer and a transversely curved earth moving blade carried thereby of guides on the convex face of said blade and scarifying teeth of a length substantially equal to the width of the blade adjustably supported in said guides andsaid teeth being curved longitudinally to coincide with the curvature of the blade.

2. The combination with a bulldozer and a transversely curved earth moving blade carried thereby, of longitudinally spaced rows of parallel guides on the convex face of said blade and longitudinally curved scarifying teeth of a length substantially equal to the width of the bladeadjustably supported in said guides, the curvature of the teeth coinciding with that of the blade.

3. The combination with a bulldozer and a transversely curved earth moving blade carried thereby of longitudinally spaced parallel rows of straps on the rear face of said blade, a scarifying tooth having a plurality of transversely extending spaced openings therein supported in each row of straps, each tooth being curved longitudinally to coincide with the curvature of the blade and. a pin projecting through at least one strap of each row for entering an opening in the tooth held therein for retaining said tooth in adjusted position with relation to the blade.

ROBERT B. BLACKMORE.

REFERENCES CITED The following references'are of record in the file of this patent:

I UNITED STATES PATE NTS Number 

